Method of making yoke ends



'.: head formed thereon.

into a second set of dies and split from its head Patented Sept.` 5,71,933v

. UNiTEofsrATEs METHOD oF MAKING YoKE ENDS Leroy 0. Johnston, Detroit;Mich., assignor to I General Motors Corporation, Detroit, Mich., a

corporation of Delawarek Application November 11', 1931 Serial No.574,319

4 claims. fol. .2g- 152) This invention relates to an improvement inyoke ends.

In the installation of the brakes on automotive vehicles, a number ofyoke ends are used and it is the object of the invention to construct ayoke end by a new method of manufacture which is much cheaper and whichwill enable the production of cheap and efficient yoke ends. f

In carrying out the invention a piece of round stock is placed in a setof dies and an oblong The piece is then put end the greaterv portion ofits length. If desired, the split yoke ends may also be formed at thesame time they are split,- the Vtools being suitably shaped. After beingsplit, the yoke end is placed in the third set of dies'where the splithead is suitably formed into the usual knobs at the ends of the yoke.The yoke end is now placed in a fourth set of dies in which it is shapedinto its final yoke form. In the performance of the above operations,the metal is preferably cold although it may be heated if desired.

On the drawing:

Figure 1 is a sectional View through the first die showing the piece ofstock in position and` the head formed thereon. y

Figure 2 shows the second set of dies (with the piece of stock takenfrom the dies of Figure 1) performing the splitting operation.

Figure 3 shows a third set of dies and the operation of forming theknobs on the end of the yoke.

Figure 4 shows the fourth operation in which the yoke endof Figure 3 isVbent to its nal form.

Figure 5.is a modification in which the knobs on the yoke end are formedat the same time that the piece of stock is split.

Figure 6 is a vmodification of the structure shown in Figure 3. y

Figure 7 shows the completed yoke end. Referring to the drawing, thenumeral 2 discloses a lower die and the numeral 4 an upper die. Thepiece of stock is indicated at 6 which is placed in the lower die 2 andthe upper die 4 forced thereon to form the oblong head 8. After theformation of the stock 6 to the shape shown in Figure 1, it istransferred to the die 10 and the tool 12 having the knife edge 14caused to descend thereon to cut or split the stock 6 at the headportion 8 separating the head into two halves 16 and 18, the stock alsobeing split the greater portion of its length. Y

'Ihe piece of stock is now transferred to the dies 20 and 22 where thesplit head portions 16 and 18 are given the form shown at 24 and 26, thedies being suitably shaped to give this formation. The upper die22 iscaused to descend on the lower die 20 in the operation. After the yokeend has been formed as shown in Figure 3, the die 22 is raised and thepunch 28 operated to push the yoke end out of the die.

. The yoke end is now transferred to the dies and 32 shown in Figure 4,the purposeof the n. dies being merely to bend or shape the yoke to itsfinal form, the completed yoke being indicated at 34 in Figures 4 and'7. The shank of the yoke is seated'in the die 30 and the die 32 presseddown to form the yoke end. When the die 32 is withdrawn it will pull theyoke 32 therewith and it may then be laterally separated. y

As an optional form of construction, the operation of Figures 2 and 3may be combined as shown by the structure of Figure 5. In this figure, abase plate 36 has an opening 38 therein for the reception of rthe shankportion of the stock 6. A pair of -dies 40 forming a V are held on thebase plate by means of the dovetail connection 42. y A tool 44 having aknife edge 46 similar to the tool 12 and knife edge 14 is caused todescend on` the bar of stock 6 to produce the split and at the same timeform the knobs 24 and 26 on the split ends 16 and 18 of the stock 6. Thedies 40 and tool 44, as well as the'dies 20 and 22 are suitably shapedto form the knobs 24 and 26. From the operation of Figure 5, the yokeend is passed through the operation shown in Figure 4.

Figure 6 is an optional construction from that shown in Figure 3. Inthis figure, the lower die 20 and the upper die 22' have a differentshape to give to the yoke end a curved formation 48 at its mid portion.The dies 20' andy 22 give to the stock 6 (taken from the structure ofFigure 2) two knob formations 24 and 26 similarly as is done in Figure3. From the dies of Figure 6, the yoke end is passed through the op-leration of Figure 4 to give it its final form.

The yoke end made by the present method produces a yoke end which isstrong and needs substantially little machining. After the yoke end ofthe length thereof, then shaping the ends, and then in forming the yokeend to its nal form, al1 of said steps taking place while the metal isin a non-heated or cold state.

2. The method of forming a yoke end consisting of forming a head onV apiece of stock, splitting the stock at the head portion part way of thelength of the stock and shaping the ends thereof, then forming the yokeend to its nal form, al1 of said steps taking place While the metal isin a non-heated or cold state.

3. The method of forming a yoke end from a bar of stock consisting offorming a head on the end of the stock while in a cold state, then insplitting the cold stock through the head and part Way of the lengththereof and simultaneous- 1y shaping the split head portion, and then inshaping the yoke end to its nal form.

4. The method of forming a yoke end from a bar of stock consisting offorming a head on the end of the stock While in a cold state, then insplitting the cold stock through the head and part Way of its length,then in shaping the cold splitend, then in shaping the cold yoke end toits final form.

' LEROY O. JOHNSTON.

